The present invention relates to rotary tooth cleaning devices and, in particular, it concerns manually powered rotary tooth cleaning devices that simultaneously brush both faces of a tooth.
Many prior-art devices, including those disclosed in U.S. Pat. No. 4,498,209, Australian Patent 449,836 and Belgium Patent 640,683, enable a user to brush both faces of his teeth at one time rather than brushing them separately with a brush having a single set of bristles. Such prior-art devices do not, however, improve the quality of the cleaning of the teeth, nor do they improve the massaging of the gums.
It has long been recognized that previously unattainable dental cleaning benefits can be achieved with a toothbrush that has twin rotary brushes that straddle the teeth and reciprocate angularly in unison. For example, in U.S. Pat. No. 4.048,690 to Wolfson, a toothbrush is disclosed which includes such rotary brushes, as well as an upwardly directed and a downwardly directed stationary brush between the rotary brushes. This toothbrush has the advantage of being able to clean both surfaces of both rows of teeth and the biting edges simultaneously. Since the toothbrush is powered, the rotary brushes are particularly effective at abradably removing plaque and sweeping it away. The stationary brushes that clean the biting surfaces of the teeth are utilized by moving the entire toothbrush. As cited in the literature, the construction of this toothbrush is to be too large and unwieldy to fit and operationally function within the mouths of persons having average or small mandibles.
U.S. Pat. No. 4,766,630 to Hegemann discloses a powered toothbrush that includes a pair of longitudinally extending, reciprocal stroke arms extending between the rotary brushes and disposed above and below their axis of rotation, respectively. The stroke arms are secured by axially directed pins between the rotary brushes, and the portion of the upper arm between the rotary brushes includes upwardly directed bristles, while the portion of the lower stroke arm includes downwardly directed bristles. When the stroke arms are oppositely reciprocated, annular movement of the rotary brushes is achieved. At the same time, the bristles on the stroke arm achieve reciprocal linear movement. However, the use of dual reciprocal arms requires a bulky body that interferes with convenient use of the brush. In addition, repeated activation of the trigger-like mechanism is tiresome and decidedly inconvenient for the user.
In U.S. Pat. No. 5,177,826 to Vrignaud et al., a powered toothbrush is provided with a pair of disk-like rotary brushes mounted for rotation about an axis generally perpendicular to the length of the brush. The rotary brushes are in axially spaced relationship and are provided with inwardly directed bristles. Between the rotary brushes, upper and lower linear brushes are mounted above and below the axis of rotation for linear reciprocating motion generally perpendicular to that axis. The upper brush has upwardly directed bristles, and the lower brush has downwardly directed bristles, and the linear brushes are mounted to the rotary brushes so as to be brought into reciprocal, linear movement when the rotary brushes are reciprocated angularly. Reciprocal motion can then be applied to one of the linear brushes or to the rotary brushes, in order to bring the entire mechanism into reciprocal motion. However, the means for providing the reciprocating, rotary motion to the rotary brush are at least partially disposed in the main body of the brush, such that the main body is bulky and unsuitable for convenient insertion and operation inside the mouth. Moreover, as in previously-described rotary brushes, the device is extremely complex and costly.
U.S. Pat No. 4,223,417 to Solow discloses a gliding, mechanized toothbrush comprising a handle and a small head that encloses a pair of brushes adapted to brush both sides of a tooth at a time. In a preferred embodiment, additional brushes clean the biting surfaces of the teeth. Preferably, the head is mounted on a swivel so that the head can be turned relative to the handle, facilitating brushing teeth in various parts of the mouth. The bristles of the brushes are made to vibrate back and forth along their axes, which is helpful in cleaning the sulcus areas, the embrasures, and the teeth. Various mechanical means can be employed to actuate the brushes, such as vibrating rods or strings or reciprocating cams or gears, but preferably the actuation of the brushes is accomplished by means of a flexible tube leading to a source of alternating vacuum and pressure. One advantage of using a source of alternating vacuum and pressure is that the main body of the toothbrush is relatively sleek relative to the cumbersome and unwieldy devices described above, however, such actuating means are clearly impractical for routine household use. Moreover, the vibratory motion does not have all the advantages manifested in the reciprocating motion of rotary brushes.
There is therefore a need for, and it would be highly advantageous to have a compact toothbrush that simultaneously cleans the front and back surfaces of the tooth using reciprocating motion provided by rotary brushes in a more convenient and efficient fashion than is known heretofore. It would be of further advantage to have a toothbrush with a mechanism that provides an effective cleaning action even for those who are unskilled or lax regarding the requisite techniques of brushing using conventional toothbrushes. It would be of further advantage to have a toothbrush that provides a cleaning action directed towards the interstitial areas that are largely inaccessible to standard toothbrushing devices. Finally, it would be greatly advantageous to have a simple and economical toothbrush that is powered manually by the user, and in a manner similar to the manner of brushing with toothbrushes of ordinary design.
It is therefore an object of the present invention to provide a tooth cleaning device that simultaneously cleans the front and back surfaces of the tooth.
It is another object of the present invention to provide effective cleaning action for the front and back surfaces of the tooth and gums, and for the interstitial areas between adjacent teeth using reciprocating motion provided by rotary brushes.
It is yet another object of the present invention to provide a tooth cleaning device that enables such effective cleaning in a more compact, simple, and convenient fashion than is known heretofore.
Another object of the present invention is to provide such a tooth cleaning device that is powered manually by the user, and in a manner similar to the manner of brushing with toothbrushes of ordinary design.
It is another object of the present invention to provide a straddle-type tooth cleaning device that guides the user along the teeth and gums, such that effective cleaning is attained even when the head of the implement is out of sight of the user.
It is a further object of the present invention to provide tooth cleaning device that enables effective cleaning action even for users who are lax or unskilled in the proper techniques of brushing.
According to the present invention is provided a straddle type tooth cleaning device for cleaning both sides of a tooth simultaneously by rotary motion, wherein said rotary motion is powered by the movement of said tooth cleaning device along the biting surface of said tooth.
In a preferred embodiment, a tooth cleaning device is provided which comprises a tooth cleaning head, including a housing with sides that straddle the tooth along both long faces, gears affixed along the inner surface of sides of said housing, tooth cleaning elements affixed along the inner side of said gears, said tooth cleaning elements being operatively spaced apart from one another, transverse the longitudinal axis of said tooth cleaning head, to form a gap therebetween, a drive mechanism comprising a drive shaft affixed to said inner surface of sides of said housing and spanning said housing, transverse the longitudinal axis of said tooth cleaning head, a drive wheel connected to said drive shaft, transfer gears affixed near ends of said drive shaft and aligned with said gears, and a handle connected to said tooth cleaning head, wherein as the tooth cleaning device travels along a row of teeth, the drive wheel rotates along the biting surface of the teeth, thereby rotating said drive shaft and said transfer gears, with the transfer gears in turn providing rotating motion to said gears affixed along the inner surface of sides of the housing and the tooth cleaning elements, such that the long faces of the tooth are cleaned simultaneously by rotary cleaning motion.
A preferred embodiment further comprises at least one brush for cleaning the biting surface of the tooth. In a preferred embodiment, the drive wheel comprises tooth cleaning means on the outer surface which contact the biting surface of the tooth.
In a preferred embodiment, each said tooth cleaning element has a brush. In another preferred embodiment, each said tooth cleaning element comprises a cluster of two or more brushes.
In another preferred embodiment, each said brush comprises bristles of varying length and orientation. In yet another preferred embodiment, the bristles are oriented towards the sulcus.
In a preferred embodiment, the gear ratio between said transfer gears and said gears affixed along the inner surface of sides of said housing ranges from about one to one to about twenty to one.
In a preferred embodiment, the drive wheel is adapted to grip the biting surface of the tooth. In another preferred embodiment, the drive wheel has a soft outer surface, thereby providing improved contact between said drive wheel and the biting surface of the tooth.
A preferred embodiment further comprises means for adjusting said gap between said tooth cleaning elements. In another preferred embodiment, these means for adjusting comprise a spring positioned between said inner surface of sides of said housing and said gear. In yet another preferred embodiment, the means for adjusting the gap are provided by pressure exerted by the sides of the housing.
In a preferred embodiment, the head of the tooth cleaning device is mounted on a swivel arrangement, such that the head can be turned relative to the handle, thereby facilitating the brushing in various parts of the mouth. In another preferred embodiment, the swivel arrangement is limited to a range of desired angles with respect to the handle.